Hi to all Dear Fiat Forum members and Fiat lovers in general,

I am asking questions to every real Fiat enthusiast especially people from Brazil,Poland and India, cause the car is very popular in these countries.

I have a Fiat Siena (178 platform), one day I was driving in the rush hour and suddenly I heard a weird sound which I couldn't identify from where it was coming, shortly afterward the car stopped working while I was in the middle of the road, I managed to get it near the curb without causing anything bad both to me or to the people, I tried to start the car and I can hear the engine cranking but it wont run, I found that I didn't lose power or electricity in the car, I stepped out and looked under the car and found a snapped belt laying beneath the engine bay and found no leaks or smoke coming from the engine, I couldn't identify which belt it is because I was nervous and pulled the laying part of the belt and moved it in the car without paying attention at that moment where it was coming from particularly,

The confusing part is that I found that the snapped part of the belt which I pulled had no teeth, unlike the timing belt, and as I know the other belts don't cause the engine to fail when something bad happens to them (alternator,water pump,power steering pump,etc...) so what makes the car unable to work, can the other belts cause the engine to fail, do the Sienas have interference or non-interference engines, and I need to know if it was the timing belt which failed but lacks the teeth, I couldn't send the car to the Fiat Agent here in the country because someone there told me that the car is too old now and there are no spare parts available with them for this model, he even claims that Italy don't produce spare parts for my model anymore now, In case the engine is affected it will be hard for me to find internal engine spares (valves,bearings,pistons,etc...)

I need your help please reply If you have any idea

the following data might help,

we bought the car (new at the time) in 2004 although I don't know the model or manufacturing year (the 2004 Siena don't look like mine)

VIN: DAA17800001509093
Design No.: 98802420
Engine No.: M06755545
Engine Type: M 605 WA 13 T 304 1.4 178 SPI HD + KLM(MISIR)
Class of cylinders: BBBB

If anyone can decode those, because the internet didn't help as expected
thanks in advance

ePER, the Fiat parts lookup system contains some vehicle data, more for later models.

Inputting your VIN gives only a little data, but it does not quite match your detail.
This is what we get.

2A - Siena Extra Europa (1997 - 2002)
178.673.1.0 Siena 1.2 MPI 8v EM.04 "EL" (Sudafrica) (Vietnam)
Engine 7045958 Manuf Date 7/3/2001

It is listed twice, once for each country above. We have found this before, but I don't think we have an answer as to why. For both countries it shows 1.2 8v and the same manufacturing date.

You may need to look a little more closely at it to determine which engine it has. You thought 1.4, the data says 1.2. A pic might help us to help you. You will need to add a few more posts before you can post pics.

If this is a 1.2 8v engine, it should have sustained no damage with a cambelt failure. As a very popular engine, finding a cambelt kit should be possible. As the car is based on the Punto we had in Europe, most of the wearable parts will be available somewhere.

thanks portland bill for your response, I am sure my car has a 1.4 liter engine, 1.4 is written on the side of the car and also the car license says it has ~1400cc (139x cc) 4 cylinder engine, anyways I don't trust the license for accurate details related to the car, I will post pics as soon as possible for the engine and for the car If I can

but I have some more few details written on the front of the car under the hood on the plate, it says that the car is assembled in egypt by Nissan egypt for Fiat egypt.

I know that the 1.4 liter engine Sienas are rare compared to the 1.2 or 1.6 liters engine, it is even listed on the wiki page of the Fiat Siena

but to consider this, are you sure about the 1.2 engine is not affected by the cambelt failure, in case I have the 1.2 engine, but what makes the 1.4 so different from the 1.2, I think they share the same design except for the total combustion chambers size (bore,stroke,etc...) can the cylinders dimensions play a role, the space swept by the pistons inside.

thanks in advance

The 1.2 8v engine was designed as a safe engine, and only became 'unsafe' when power was increased above the 60hp. Later engines, in the 500 and late Pandas produce 69hp with variable valve timing. These are considered 'unsafe', but you may get away with it if the engine was in a low power mode when failure occurred.
Your age of vehicle was before the variable valve timing.

The 1.4 is a less popular engine here in the UK, so little discussion about failures, so I just don't know.

One bit of diagnosis with little dismantling is to check the valve clearances.
Obviously, with the cambelt broken normal procedure for this won't work.
With the plugs out, stick a small screwdriver or rod of some sort into a plughole (make sure it is not possible to lose it) and gently rotate the engine to put the pistons half-way down the bore. This is usually the normal timing position for the 1.2, so probably for the 1.4 too.
Now you can rotate the camshaft without fear of hitting a piston, so the valve clearances can be checked. Any with an excessive clearance probably means a bent valve, not closing properly.
If they all look OK, pop a new cambelt on.

On the VIN plate might be an engine code, e.g. 188A.4000 or similar. Tell us what that is, it will identify the engine type, and we can direct you to the Forum for other vehicles using the same engine. I believe the Siena was based on the Punto of the same era, but not sure how much carries over.

What do you mean by low power mode, does it mean the engine rpm, if yes, I was driving after the traffic opened when the failure occurred so that means a rpm of something below and never reached 3000 rpm (but during the traffic I was moving so slowly and idling during the traffic, rpm of something between 1000 and 2000 ) but I did something stupid before I realized the snapped belt, I cranked the engine few times, does that has an effect on the engine ?

Some of the car's related info:

VIN: DAA17800001509093
Design No.: 98802420
Engine No.: M06755545
Engine Type: M 605 WA 13 T 304 1.4 178 SPI HD + KLM(MISIR)
Class of cylinders: BBBB

The following info was obtained from the plate located under the hood

Assembled by Nissan Egypt for Fiat Auto Egypt industrial co. S.A.E under license of Fiat Auto SPA Italy
Model (A) 178 CXC 1A AE
GVM (B) 1510
GCM (C) 2610
GA (D) 800
CA (E) 800

The variable valve timing on those engine with it change the valve timing as the revs increase to develop more power. At lower revs, the timing is similar to the earlier engine, so valves should not hit pistons. Not very important, as theory will be less important than whether or not it has sustained damage.

Having cranked it over, were there any noises when cranking, which would suggest that the pistons were hitting valves? Don't crank it again to remind yourself!
Turn it over gently by hand, at least two complete turns. With the plugs out. You should be able to feel if pistons touch anything, but checking the valve clearances will help. If that feels ok, get a belt kit, fit it and try to start it.

So the probability of sustaining a damage to the engine is lower when the engine is rotating at low rpm ?

I don't think I heard anything other than the cranking noise but I'm not sure, anyways I won't crank it again as you said.

before trying the diagnosis myself, I need to know what plugs do you mean the spark plugs ?

Yes, with the spark plugs out, it is easier to turn, as there is no compression, so you might feel if anything hits.

UPDATE

sorry for the late reply, I managed to get a mechanic to check on the vehicle, he claims that the timing belt is well and nothing happened to the valves, (I hope he's right), he claims that the alternator belt snapped and then it destroyed/affected a "SENSOR" which prevents the car from getting a spark and therefor won't run (lack of spark)

the sensor itself is all good and well but "the connection or the place which holds/connects the sensor is broken/affected by the snapped alternator belt" I don't know if this is technically possible.

anyway, If anybody know which part is the one he meant/be replaced, I didn't understand him 100 %, they use their local definitions, he even didn't name/label it, he said and I translate into english "the aluminum part/body which encloses the crankshaft and holds the sensor" IS IT THE CRANKCASE ?

And by the way, which sensor is meant, I mean which sensor is responsible for distributing the spark through the spark plugs to the combustion chamber ?

my regards,

Positioned close to the crankshaft pulley is a bracket that holds the crank sensor. The sensor reads the pulley as it rotates to tell the ECU the engine position. The sensor is very close to the pulley, so is vulnerable if the auxiliary belt breaks.
I can't find the bracket on the parts lookup system. This might mean it is part of the crankcase, which is bad news, or it may be a separate part, but like many others, is not in a logical place in the parts listings.
Your mechanic can see easily whether it is replaceable, either from a Fiat dealer or a scrap car, so ask him to show you, or take a pic.

Good luck.

yeah, there are two main ways to get spare parts over here, either through the dealer (local FIAT Agent) which will be new parts, or through the independent parts shops/dealers which sell parts from scraps imported from abroad and still has an acceptable quality/health, I prefer good quality/healthy scraps parts, when I discussed the situation with him, he said that it's a one-part item so maybe I will change the whole crankcase, till now I decided to buy the needed part from a scrap dealer, and I will post as I get the part and the job done

If I found any cracks/bends I will get the new spare part instead, but the local FIAT agent/importer, their representative claims that my car has no spare parts available with them because the car is old, in this case I will check on the ePER for the crankcase

This tread belongs in the Palio section, of course...

hey dear Portland Bill, I fixed my car with the mechanic and everything now is running fine, I was lucky to find that the bracket is a separate part from the crankcase, I got a used one from another car (bough it from the owner) and bought also it's gasket and a new auxiliary belt (for alternator and power steering pump i think) and replaced the broken bracket and now the car is running good, I also bought some new headlight bulbs (2 low beam + 2 high beam)

I learned that my car has no distributor for the spark plugs, I have this crankshaft position sensor instead, would you please explain to me how does that sensor govern the spark plugs ?

I will post photos for the broken bracket and the bad auxiliary belt, I found that my car has 3-4 belts (cam belt, 2-3 auxiliary belts) I need to know which belt drives the water pump, a/c compressor, alternator, power steer pump ?

Have a look at ePER on top of this page, if there's no Siena, search for the 1,6 Palio engine.

Mando said:

hey dear Portland Bill, I fixed my car with the mechanic and everything now is running fine, I was lucky to find that the bracket is a separate part from the crankcase, I got a used one from another car (bough it from the owner) and bought also it's gasket and a new auxiliary belt (for alternator and power steering pump i think) and replaced the broken bracket and now the car is running good, I also bought some new headlight bulbs (2 low beam + 2 high beam)

I learned that my car has no distributor for the spark plugs, I have this crankshaft position sensor instead, would you please explain to me how does that sensor govern the spark plugs ?

I will post photos for the broken bracket and the bad auxiliary belt, I found that my car has 3-4 belts (cam belt, 2-3 auxiliary belts) I need to know which belt drives the water pump, a/c compressor, alternator, power steer pump ?

Click to expand...

Hi, Good that the car is fixed, well done.

Modern cars do not use a distributor to send a spark to the plugs. A distributor would wear eventually, and give variable timing and was always vulnerable to damp.
Now we have one ignition coil for each pair of cylinders, or an individual coil on each plug. I've not looked up the details of your engine, but it is probably the 'normal' two coils to fire four plugs.
The crank sensor measures the crank position and the ECU (Electronic Control Unit) uses this to know engine speed and position. It also uses other inputs, such as engine temperature and throttle position and then fires the coils at the correct time. The ECU is able to change the timing for each cylinder more accurately and more frequently than a distributor could, so helping control the engine for best efficiency and lowest emissions. Most engines also have a camshaft sensor as well and the ECU will compare these.
If the crank position sensor dies, the ECU does not know the engine is turning, so will not fire the plugs.
With a normal 4 cylinder engine, pistons 1 & 4 go up and down together, and half a turn away, pistons 2 & 3 go together. With each pair reaching the top, one is on compression, ready to fire, whilst the other is on the exhaust stroke. Each coil has two leads, one for each of the pair of cylinders, so both plugs fire together. The one on the exhaust stroke gets a spark, that does nothing, a wasted spark. This has been used on Japanese motorcycles for many years.

The 1,6-16V engine used in the Siena, is the same engine used in many other Fiat models, like the Brava(o), Marea, Multipla, Stilo, etc. etc.

portland_bill said:

Hi, Good that the car is fixed, well done.

Modern cars do not use a distributor to send a spark to the plugs. A distributor would wear eventually, and give variable timing and was always vulnerable to damp.
Now we have one ignition coil for each pair of cylinders, or an individual coil on each plug. I've not looked up the details of your engine, but it is probably the 'normal' two coils to fire four plugs.
The crank sensor measures the crank position and the ECU (Electronic Control Unit) uses this to know engine speed and position. It also uses other inputs, such as engine temperature and throttle position and then fires the coils at the correct time. The ECU is able to change the timing for each cylinder more accurately and more frequently than a distributor could, so helping control the engine for best efficiency and lowest emissions. Most engines also have a camshaft sensor as well and the ECU will compare these.
If the crank position sensor dies, the ECU does not know the engine is turning, so will not fire the plugs.
With a normal 4 cylinder engine, pistons 1 & 4 go up and down together, and half a turn away, pistons 2 & 3 go together. With each pair reaching the top, one is on compression, ready to fire, whilst the other is on the exhaust stroke. Each coil has two leads, one for each of the pair of cylinders, so both plugs fire together. The one on the exhaust stroke gets a spark, that does nothing, a wasted spark. This has been used on Japanese motorcycles for many years.

Click to expand...

thanks mate for those precious information, I will post photos soon to give you a look on the car and it's engine components for confirmation, looking forward for your confirmation

Peter Pick-Up said:

The 1,6-16V engine used in the Siena, is the same engine used in many other Fiat models, like the Brava(o), Marea, Multipla, Stilo, etc. etc.

Click to expand...

yeah my friend you're absolutely right, I think all of the 178 platform models like the Siena and Palio with all their variations share some of the engines (the overall Powertrain) and the platform too, but my Siena car is 1.4 L which is not so popular compared to the 1.2 L or the 1.6 L Sienas